Resolve "Problems with background I/O"

Closes #440 (closed)

src/virtmat/language/utilities/textx.py

@@ -142,7 +142,7 @@ def display_exception(func):
             return func(*args, **kwargs)
         except Exception as err:
             print('\n', file=sys.stderr)
-            traceback.print_exception(err, file=sys.stderr)
+            traceback.print_exception(*sys.exc_info(), file=sys.stderr)
             print('\n', file=sys.stderr)
             raise err
     return decorator